As far as the cause of bullying, it seems that even kids who have been raised correctly can give into the negative pressure around them. It really is quite sad.
i agree, the first stimulus comes from the family environment , then friends and school and ofc from our own selves. We can't for example be 16 or 18 or 25 and bully others and blame our family and peer pressure for that. They need to "grow up"
As you said it's quite sad!